Micronized Wood Preservative Formulations

ABSTRACT

The present invention provides wood preservative compositions comprising micronized particles. In one embodiment, the composition comprises dispersions of micronized metal or metal compounds. In another embodiment, the wood preservative composition comprises an inorganic component comprising a metal or metal compound and organic biocide. When the composition comprises an inorganic component and an organic biocide, the inorganic component or the organic biocide or both are present as micronized particles. When compositions of the present invention are used for preservation of wood, there is minimal leaching of the metal and biocide from the wood.

This application claims priority to U.S. Provisional Application No.60/461,547, filed Apr. 9, 2003. This application also claims priority toU.S. Provisional Application No. 60/518,994, filed Nov. 11, 2003, thedisclosure of which is incorporated herein by reference.

FIELD OF THE INVENTION

The present invention is related generally to the field of woodpreservatives and more particularly to a wood preservative compositioncomprising micronized particles.

BACKGROUND OF THE INVENTION

Wood preserving compositions are well known for preserving wood andother cellulose-based materials, such as paper, particleboard, textiles,rope, etc., against organisms responsible for the destruction of wood,including fungi and insects. Many conventional wood preservingcompositions contain copper amine complexes. Copper amine complexes havebeen used in the past because the amine solubilizes the copper inaqueous solutions. The copper in such copper amine complexes is obtainedfrom a variety of copper bearing materials, such as copper scrap,cuprous oxide, copper carbonate, copper hydroxide, a variety of cuprousand cupric salts, and copper bearing ores. The amine in such copperamine complexes is normally obtained from an aqueous solution of ammoniaand ammonium salts, such as ammonium carbonate, and ammonium sulfate,ethanolamines, et cetera. For example, U.S. Pat. No. 4,622,248 describesforming copper amine complexes by dissolving copper (II) oxide [CuO](also known as cupric oxide) in ammonia in the presence of ammoniumbicarbonate.

The disadvantage of using ammonia as a copper solubilizing agent lies inthe strong odor of ammonia. Additionally, copper ammonia preservativescan affect the appearance of the treated wood giving surface residuesand undesirable color. In recent years, many amine-containing compounds,such as the ethanolamines and aliphatic polyamines, have been used toreplace ammonia to formulate water-soluble copper solutions. Thesecompounds were chosen because of their strong complexing ability withcopper and because they are essentially odorless. U.S. Pat. No.4,622,248 discloses a method of preparing copper amine complexes bydissolving a mixture of copper (II) carbonate [CuCO₃] and copper (II)hydroxide [Cu(OH)₂] in ethanolamine and water. The complexing amine(i.e., the ligand) and copper (II) ion combine stoichiometrically andthus the weight ratio of reagents will be different for each complexingamine. However, copper amine based preservatives have higher copper lossdue to leaching as compared to traditional copper based preservativessuch as chromated copper arsenate (CCA).

In addition to metal biocides, existing wood preservatives can alsocontain organic biocides. However, many organic biocides currently inuse are not water soluble. Therefore, solubilizing agents, surfactantsand wetting agents are often added to either solubilize or formemulsions of the organic biocide to formulate a product that is suitablefor the treatment of wood or other cellulose substrates.

However, the solubilizing agents, surfactants, and wetting agents arecostly and the use of these products may result in enhanced leaching ofthe biocides when the treated material comes into contact with moisture.Such enhanced leaching is considered to be the result of thesolubilizing agents, surfactants and wetting agents which remain in thewood after treatment. Because these compounds continue to cause leachingof the metal and/or biocide from the treated wood, field performanceproblems or environmental issues can result.

Despite many efforts to address these deficiencies in existing woodpreservatives, there has been an unmet need to produce aqueousmetal-based preservatives that are suitable for treating wood and othercellulose-based materials while minimizing the undesirable leaching ofmetal ions and/or biocide from treated materials when exposed to water.This need is met by the invention disclosed herein.

SUMMARY OF THE INVENTION

The present invention provides micronized compositions for preservationof wood. In one embodiment, the compositions comprise metal or metalcompounds as micronized particles.

In another embodiment, the compositions comprise metal or metalcompounds and organic biocides. The metal is in an insoluble (micronizedform). The metal compounds may be in a soluble form or in a waterinsoluble (micronized) form. The organic biocides may be soluble orwater insoluble (micronized). In the compositions of this embodiment, atleast one component (either a metal/metal compound or a biocide) ismicronized.

Accordingly, in one embodiment is provided a wood preservativecomposition comprising micronized metal, metal compounds or combinationsthereof.

In another embodiment is provided a wood preservative compositioncomprising a micronized metal or metal compound and a soluble organicbiocide.

In another embodiment is provided a wood preservative compositioncomprising micronized metal/metal compounds and micronized organicbiocides.

In another embodiment is provided a composition comprising soluble metalcompound and micronized organic biocides.

Also provided is a method for using the compositions of the presentinvention. The method comprises the step of contacting a cellulosicmaterial, such as wood, with a composition of the present invention.When the compositions of the present invention are used for preservationof wood, there is minimal leaching of the metal or metal and the biocidefrom wood.

In one embodiment, the preferred metal for wood preserving typeapplications is copper in the form of a copper compound having aparticle size 0.005 microns to 25.0 microns. The copper compound canoptionally be mixed with a variety of water soluble and/or waterinsoluble biocides and then vacuum impregnated, vacuum/pressure or dipimpregnated into cellulosic material by standard methods to effectivelypreserve the material from agents that degrade cellulosic material suchas fungi, insects, bacteria etc.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1A is a comparison of copper leaching from wood treated with coppermonoethanolamine (copper mea) vs. micronized copper hydroxide at copperretentions of 0.1 pounds per cubic foot (pcf) and 0.2 pcf according toAmerican Wood Preservers' Association (AWPA) Standard E11-97 “StandardMethod of Determining the Leachability of Wood Preservatives”.

FIG. 1B is a comparison of copper leaching from wood treated with acommercial copper based formulation ACQ-Type D and micronized coppercarbonate plus dimethyldidecylammonium carbonate/bicarbonate (quat) atpreservative retentions of 0.25 pcf and 0.40 pcf. The leaching test wasconducted following the procedure described in AWPA Standard E11-97“Standard Method of Determining the Leachability of Wood Preservatives”.

FIG. 2 depicts the anatomy of coniferous wood.

FIG. 3 depicts the border pit structure for coniferous wood.

FIG. 4A depicts the uniform copper penetration in wood treated withmicronized copper hydroxide according to AWPA Standard A3-00 “StandardMethod for Determining Penetration of Preservatives and FireRetardants”.

FIG. 4B depicts the uniform copper penetration in wood treated withmicronized copper carbonate plus quat. The determination of copperpenetration was conducted following the procedures described in AWPAStandard A3-00 “Standard Method for Determining Penetration ofPreservatives and Fire Retardants”.

FIG. 5 depicts the uniform particle distribution of cupric oxide throughthe cells of the wood treated with micronized CuO.

DETAILED DESCRIPTION OF THE INVENTION

Unless stated otherwise, such as in the examples, all amounts andnumbers used in this specification are intended to be interpreted asmodified by the term “about”. Likewise, all elements or compoundsidentified in this specification, unless stated otherwise, are intendedto be non-limiting and representative of other elements or compoundsgenerally considered by those skilled in the art as being within thesame family of elements or compounds. The term “micronized” as usedherein means a particle size in the range of 0.005 to 25 microns. Theterm “preservative” as used herein means a composition that renders thematerial to which it is applied more resistant to insect, fungal andmicrobial attack than the same material without having the compositionapplied. The term “particle size” refers to the largest axis of theparticle, and in the case of a generally spherical particle, the largestaxis is the diameter.

The wood preservative compositions of the present invention comprise aninorganic component comprising a metal, metal compound or combinationsthereof and optionally one or more organic biocides. Accordingly, thepresent invention provides micronized wood preservatives comprising oneor more metal or metal compounds with or without one or more organicbiocides. When the composition comprises both the metal/metal compoundsand the organic biocides, the metal or metal compounds or the organicbiocides are present as water insoluble micronized particles. In oneembodiment, both the inorganic component and the organic biocide arepresent as micronized particles.

These compositions are used for treatment of cellulosic material such aswood. The leaching of metal from the treated wood is less for thepresent compositions than that observed from wood treated withnon-micronized compositions.

A preferred metal is copper. Accordingly, in one embodiment, copper orcopper compounds are used. The copper or copper compounds such ascuprous oxide (a source of copper (I) ions), cupric oxide (a source ofcopper (II) ions), copper hydroxide, copper carbonate, basic coppercarbonate, copper oxychloride, copper 8-hydroxyquinolate, copperdimethyldithiocarbamate, copper omadine, copper borate, copper residues(copper metal byproducts) or any suitable copper source can be used asmicronized particles having a particle size between 0.005 microns to 25microns. These particles exhibit a relatively low solubility in water.

The micronized particles can be obtained by wetting/dispersing andgrinding copper compounds using a commercially available grinding mill.Alternatively, the micronized copper compounds may also be purchasedfrom commercial sources, which generally need to be ground further to beuseful for wood preservation. For example, micronized copper hydroxidecan be obtained from Phibro-Tech, Inc., Sumter, S.C. and ground furtherfor use in the present invention. Micronized cupric oxide can also beobtained from Nanophase Technologies Corporation, Romeoville, Ill.

The copper source can be mixed with water with or without addition of acommercially available rheological additive such as a cellulosicderivative to form a finely dispersed suspension which can be mixed witha biocide to form a preservative system which is suitable to treat andprotect wood from agents causing degradation. Other metals or metalcompounds as well as transition metals or transition metal compounds(including the lanthanide and actinide series elements) such as tin,zinc, cadmium, silver, nickel, etc. and compounds thereof can be used inplace of copper and copper compounds. The resulting metal dispersion orthe metal biocide fluid dispersion are suitable for the preservation ofwood and other cellulose-based materials.

The organic biocides useful in the present invention can be watersoluble as well as water insoluble. Such organic biocides includingfungicides, insecticides, moldicides, bactericides, algaecides etc. arewell known to those skilled in the art and include azoles, quaternaryammonium compounds, borate compounds, fluoride compounds andcombinations thereof.

Some non-limiting examples of water soluble biocides are quaternaryammonium compounds, such as alkyldimethylbenzylammonium chloride,dimethyldidecylammonium chloride, dimethyldidecylammoniumcarbonate/bicarbonate and the like.

Water insoluble organic biocides are also well known. Some non-limitingexamples of water insoluble organic biocides are shown in Table 1.

TABLE 1 Organic Biocides Useful for Wood Protection Name Formula andCAS# Azoles: Cyproconazole C₁₅H₁₈ClN₃O: 94361-06-5 PropiconazoleC₁₅H₁₇Cl₂N₃O₂: 60207-90-1 Tebuconazole C₁₆H₂₂ClN₃O: 107534-96-3 Busan(TCMTB) C₉H₆N₂S₃: 21564-17-0 2-(thiocyanatomethylthio) benzothiazoleChlorothalonil C₈Cl₄N₂: 1897-45-6 Dichlofluanid C₉H₁₁Cl₂FN₂O₂S₂:1085-98-9 Isothiazolone: Kathon 930 C₁₁H₁₇Cl₂NOS: 64359-81-5 Kathon WTC₄H₄ClNOS: 26172-55-4 Methylisothiazolinone C₄H₅NOS: 2682-20-4Benzisothiazolin-3-one C₇H₅NOS: 2634-33-5 2-octyl-3-isothiazoloneC₁₁H₁₉NOS: 26530-20-1 Imidacloprid C₉H₁₀ClN₅O₂: 138261-41-3 IodopropynylButylcarbamate C₈H₁₂INO₂: 55406-53-6 (IPBC) Pyrethroids: BifenthrinC₂₃H₂₂ClF₃O₂: 82657-04-3 Cypermethrin C₂₂H₁₉Cl₂NO₃: 52315-07-8Permethrin C₂₁H₂₀Cl₂O₃: 52645-53-1 Chitin 1398-61-4 Chitosan 9012-76-4Clorpyrifos C₉H₁₁Cl₃NO₃PS: 2921-88-2 4-cumylphenol C₁₅H₁₆O: 599-64-4Fipronil C₁₂H₄Cl₂F₆N₄OS: 120068-37-3 Carbendazim C₉H₉N₃O₂: 10605-21-7Cyfluthrin C₂₂H₁₈Cl₂FNO₃: 68359-37-5 4-alpha-Cumylphenol C₁₅H₁₆O:599-64-4

Other biocides such as insecticides, mold inhibitors, algaecides,bactericides and the like may also be added to the composition of thepresent invention.

The insoluble biocides can be micronized into particles of submicronsize ranging from 0.005 micrometers to 25 micrometers using a grindingmill. The particles are dispersed in standard dispersants such asacrylic copolymers, aqueous solution of copolymers with pigment affinitygroups, modified polyacrylate, acrylic polymer emulsions, modifiedlignin and the like.

In one embodiment, micronized metal or metal compounds such as a coppercompound is mixed with an insoluble micronized organic biocide. Themetal or metal compound and the insoluble biocide may be micronizedseparately and then mixed or may be mixed first and then micronized.

In another embodiment, the metal compound is water soluble. Example of asuitable water soluble metal compounds are copper sulfate, copperacetate and copper nitrate. In this embodiment, an aqueous solution ofthe copper compound is prepared and then a micronized dispersion of anorganic biocide is added to it.

Non-biocidal products such as water repellants (such as wax emulsions),colorants, emulsifying agents, dispersants, stabilizers, UV inhibitors,enhancing agents (such as trialkylamine oxides and alkoxylated diamines)and the like may also be added to the composition disclosed herein tofurther enhance the performance of the system or the appearance andperformance of the resulting treated products. Those skilled in the artwill recognize that some of these agents may also have some biocidalproperties.

The trialkylamine oxides have the following structure.

where R₁ is a linear or cyclic C₈ to C₄₀ saturated or unsaturated groupand R₂ and R₃ independently are linear C₁ to C₄₀ saturated orunsaturated groups.

The alkoxylated diamines have the following structure:

where n is an integer which can vary from 1 to 4, R₁, R₂ and R₃ areindependently selected from the group consisting of hydrogen, methyl,ethyl and phenyl, and a, b and c are each integers which can be 1 to 6,and R₄ is fatty alkyl of C₈ to C₂₂.

When wood is treated with micronized wood preservatives formulationsdisclosed herein, metal leaching is reduced. For example, as shown inFIG. 1A, when wood is treated with Cu-MEA composition the leaching ofcopper is about 12% and 24% respectively for 0.1 pcf (pounds per cubicfeet) copper and 0.2 pcf copper. In contrast when the wood is treatedwith a micronized composition of the present invention the leaching wasonly about 2% and 1% respectively for the 0.1 pcf copper and 0.2 pcfcopper. Copper leaching was evaluated following the procedures describedin American Wood Preservers' Association Standard E11-97.

Similarly, FIG. 1B is a comparison of copper leaching from wood treatedwith a commercial copper based formulation ACQ-Type D and micronizedcopper carbonate plus dimethyldidecylammonium carbonate/bicarbonate(quat) at preservative retentions of 0.25 pcf and 0.40 pcf. The leachingtest was conducted following the procedure described in AWPA StandardE11-97 “Standard Method of Determining the Leachability of WoodPreservatives”. It can be seen that wood treated with micronized coppercarbonate based formulation demonstrated much greater copper leachingresistance than the wood treated with the commercially availablepreservative Ammoniacal Copper Quat (ACQ)-Type D.

Also important is the penetration of the dispersion formulation into thewood's or other cellulose-based material's cellular structure. If thecopper source used in formulating the dispersion formulation disclosedherein has a particle size in excess of 25 microns, the particles may befiltered by the surface of the wood and thus may not be uniformlydistributed within the cell and cell wall. As shown in FIG. 2, theprimary entry and movement of fluids through wood tissue occursprimarily through the tracheids and border pits. Tracheids have adiameter of about thirty microns. Fluids are transferred between woodcells by means of border pits.

The overall diameter of the border pit chambers typically varies from aseveral microns up to thirty microns while, the diameter of the pitopenings (via the microfibrils) typically varies from several hundredthsof a micron to several microns. FIG. 3 depicts the border pit structurefor coniferous woods.

When wood is treated with micronized preservative formulation, if theparticle size of the micronized preservative is less than the diameterof the pit openings, a complete penetration and a uniform distributionof micronized preservative in wood is expected. FIG. 4A depicts thecomplete copper penetration in wood treated with micronized copperhydroxide according to AWPA Standard A3-00 “Standard Method forDetermining Penetration of Preservatives and Fire Retardants”. A uniformblue was observed indicating the presence of copper. FIG. 4B depicts thecomplete copper penetration in wood treated with micronized coppercarbonate plus quat. Again, a uniform blue color was observed indicatingthe presence of copper. The determination of copper penetration wasconducted following the procedures described in AWPA Standard A3-00“Standard Method for Determining Penetration of Preservatives and FireRetardants”. FIG. 5 depicts the uniform particle distribution of cupricoxide through the cells of the wood treated with micronized CuO throughthe observation of Scanning Electron Microscope (SEM). The particleswere confirmed to be copper compounds by the use of SEM-Energy DispersedX-ray Analysis (EDXA).

Particle size of the metal, metal compounds or organic biocide used inthe dispersion formulation disclosed herein typically does not exceed 30microns or the metal and or organic biocide used in conjunction with themetal tends to be filtered by the surface of the wood thus not attaininga desired penetration and fluid flow through the wood tissue. In oneembodiment particle size of the micronized particles used in thedispersion formulation disclosed herein can be between 0.005-10 microns.In another embodiment, the particle size is between 0.005 to 1.0 micron.In another embodiment, the particle size is between 0.05 to 10.0microns. If a more uniform penetration is desired, particle size of themetal/metal compounds or the organic biocide used in the dispersionformulation disclosed herein can be between 0.05-1.0 microns.

The present invention also provides a method for preservation of wood.In one embodiment, the method comprises the steps of treating wood witha composition (treating fluid) comprising a dispersion of waterinsoluble micronized metal and/or metal compounds. In anotherembodiment, wood is treated with a composition comprising a dispersionof micronized metal and/or metal compounds and organic biocides, whereinthe organic biocides are soluble or present as water insolublemicronized particles. The size of the micronized particles for themetal/metal compounds and organic biocide is between 0.005 to 25microns, preferably between 0.005 to 10 microns, more preferably between0.05 to 10 micron and even more preferably between 0.05 to 1.0 microns.In another embodiment, the wood is treated with a composition comprisingsoluble metal compounds and micronized organic biocides.

The treating fluid may be applied to wood by dipping, soaking, spraying,brushing, or any other means well known in the art. In a preferredembodiment, vacuum and/or pressure techniques are used to impregnate thewood in accord with this invention including the standard processes,such as the “Empty Cell” process, the “Modified Full Cell” process andthe “Full Cell” process, and any other vacuum and/or pressure processeswhich are well known to those skilled in the art.

The standard processes are defined as described in AWPA Standard C1-03“All Timber Products—Preservative Treatment by Pressure Processes”. Inthe “Empty Cell” process, prior to the introduction of preservative,materials are subjected to atmospheric air pressure (Lowry) or to higherair pressures (Rueping) of the necessary intensity and duration. In the“Modified Full Cell”, prior to introduction of preservative, materialsare subjected to a vacuum of less than 77 kPa (22 inch Hg) (sea levelequivalent). A final vacuum of not less than 77 kPa (22 inch Hg) (sealevel equivalent) shall be used. In the “Full Cell Process”, prior tointroduction of preservative or during any period of condition prior totreatment, materials are subjected to a vacuum of not less than 77 kPa(22 inch Hg). A final vacuum of not less than 77 kPa (22 inch Hg) isused.

The following examples are provided to further describe certainembodiments of the invention but are in no way meant to limit the scopeof the invention. Examples 1 through 5 demonstrate the formulation ofthe concentrated dispersions of copper compounds and the concentrateddispersions of copper compounds comprising various organic biocides.Examples 6 through 14 demonstrate the preparation of treating fluidsusing concentrated dispersions for the treatment of wood.

EXAMPLE 1

500 g of copper hydroxide were added to a container containing 1091.7grams of water and 75.0 grams of commercially availabledispersants/wetting agents. The mixture was mechanically stirred for 5minutes and then placed in a grinding mill. The sample was ground forabout 30 minutes, and a stable dispersion containing about 30% copperhydroxide was obtained. The particle size of the copper hydroxidedispersion was analyzed by Horiba LA-910 Particle Size DistributionAnalyzer (PSDA). The average particle size was 0.195 micrometers (um)with a distribution range of 0.04 um to 1.5 um.

EXAMPLE 2

1000 grams of basic copper carbonate was mixed with 2158.3 grams ofwater and 175.0 grams of commercially available wettingagents/dispersants. The mixture was mechanically stirred for 10 minutes.The mixture was then placed in a grinding mill and ground for about 20minutes. A stable dispersion was obtained with an average particle sizeof 0.199 micrometers.

EXAMPLE 3

1000 grams of basic copper carbonate and 20 grams of tebuconazole weremixed with 3780 grams of water and 200 grams of wettingagents/dispersants. The mixture was mechanically stirred for about 10minutes. The mixture was then placed in a grinding mill and ground forabout 30 minutes. A stable dispersion containing 25% basic coppercarbonate and 0.5% tebuconazole was obtained with an average particlesize of 0.200 micrometers.

EXAMPLE 4

300 grams of copper 8-hydroxyquinolate (Cu-8) were mixed with 855 gramsof water and 45 grams of dispersants. The mixture was mechanically mixedfor about 5 minutes and placed in a grinding mill. The mixture wasground for about 30 minutes and a stable dispersion containing 25% Cu-8was obtained with an average particle size of 0.282 micrometers.

EXAMPLE 5

A stable cupric oxide (CuO) dispersion containing about 30% CuO wassupplied by Nanophase Technologies, Inc. The average particle size wasabout 0.1 micrometers. This can be mixed with organic soluble ormicronized biocides.

EXAMPLE 6

38.5 g of cupric hydroxide dispersion from Example 1 was mixed with 7.5g of N,N-dimethyl-1-dodecylamine-N-oxide (AO) and 2954.0 g of water toproduce a preservative treating fluid containing 0.385% cupric hydroxideand 0.25% AO. The fluid was then used to treat 2″×4″×10″ samples ofsouthern pine sapwood, and sealed with epoxy resin, using an initialvacuum of 28″ Hg for 15 minutes, followed by a pressure cycle of 135 psifor 25 minutes and a final vacuum of 27″ Hg for 10 minutes. Theresulting treated wood was weighed and found to have doubled its weight.The treated sample was cut and the cross sections sprayed with a copperindicator to determine copper penetration following the proceduredescribed in American Wood Preservers' Association Standard A3-00, andthe blue color indicates the presence of copper. The sample was found tohave 100% uniform distribution of copper throughout the cross section asin FIG. 4A. As a comparison, FIG. 4A also showed the cross section ofuntreated wood.

EXAMPLE 7

50.0 g CuO dispersion from Example 5 were mixed with 2942.5 g of waterand 7.5 g of didecyldimethylammonium chloride. The product was mixeduntil uniformly dispersed and the treating solution containing thefollowing compositions was obtained:

Components Percent Cupric Oxide 0.50 Didecyldimethylammonium Chloride0.25A southern pine stake measuring 1.5″×3.5″×10″ was placed in a laboratoryretort with a vacuum of 27″ Hg for 15 minutes. The treating solution wasthen pumped into the retort and the retort pressurized to 130 psi for 30minutes. The solution was drained from the retort and the test stakeweighed. Based on the weight pickup, the test stake doubled its weightand showed uniform penetration of the cupric oxide throughout the woodcross section. A sample taken from the center portion of the treatedwood was submitted for scanning electron microscopy (SEM) analysis, andthe SEM result indicated the uniform particle distribution in wood asshown in FIG. 5.

EXAMPLE 8

4000 g of treating fluid containing 0.31% of cupric oxide and 0.16%didecyldimethylammonium carbonate were prepared by mixing CuO dispersionfrom Example 5 and didecyldimethylammonium carbonate. The fluid was usedto treat 2″×4″×10″ southern pine samples by placing the samples in achamber and drawing a 27″ Hg vacuum for 10 minutes. The treating fluidwas then drawn into the chamber and allowed to stay in contact with thewood cubes for 15 minutes. The fluid was pumped from the chamber and theresulting wood had more than doubled its weight. Cross sections of thecubes showed 100% copper penetration.

EXAMPLE 9

A preservative treating formulation was prepared by adding 0.15 kg ofcopper carbonate dispersion from Example 2 to 0.025 kg of N,N-dimethyl-1-hexadecylamine-N-oxide and 4.825 kg of water. This fluidwas allowed to mix until a homogenous fluid was prepared. This fluid wasused to treat southern pine test stakes measuring 0.156×1.5×10.0 inchs(4×38×254 mm) by the full-cell process. The resulting stakes showed auniform distribution of copper throughout the wood cells. The treatedtest stakes were installed in the field to evaluate the fieldperformance of the preservative following the procedure described inAWPA Standard E7-01 “Standard Method of Evaluating Wood Preservatives byField Tests with Stakes”. The test results indicated that the treatedstakes were resistant to decay and insect attack. The fluid was alsoused to treat southern pine wood cube blocks measuring ¾″×¾″×¾″ (19mm×19 mm×19 mm). The treated cubes were exposed to several test fungi toevaluate the bio-efficacy of the preservative formulation following theprocedure described in AWPA Standard E10-01 “Standard Method of TestingWood Preservatives by Laboratory Soil-Block Cultures”. Upon thecompletion of the soil-block test, the cubes were found to have lessthan 2.0% weight loss, indicating essentially no fungal attack to thetreated cubes. In comparison, untreated wood cubes had approximately 50%weight loss after being exposed to the test fungi. The soil block testresults indicated wood treated the above preservative formulation wasresistant to fungal attack.

EXAMPLE 10

A preservative treating composition was prepared by adding 0.1 kg ofdispersion from Example 3 to 4.9 kg of water. The resulting fluidcontained 0.50% copper carbonate and 0.01% tebuconazole. This fluid wasthen used to treat full-size lumber using the full-cell process whereinthe wood is initially placed under a vacuum of 30″ Hg for 30 minutes,followed by the addition of the treating solution. The system was thenpressurized for 30 minutes at 110 psi. A final vacuum of 28″ Hg for 30minutes was applied to the wood to remove residual liquid. The wood wasfound to contain a uniform distribution of copper throughout the crosssections and is resistant to fungal and insect attack.

EXAMPLE 11

54 g of dispersion from Example 3 and 7.5 g ofN,N-dimethyl-1-hexadecylamine-N-oxide (AO) were mixed with 2938.5 gramsof water to obtain a preservative treating fluid containing 0.45%carbonate, 0.009% tebuconazole and 0.25% AO. The resulting fluid wasused to treat red pine lumber using a modified full-cell process. Theresulting stakes were air-dried and found to a uniform distribution ofcopper throughout the cross sections and were resistant to fungal andinsect attack.

EXAMPLE 12

A preservative treating fluid was prepared by adding 16.0 g of Cu8-hydroxyquinolate (Cu-8) dispersion from Example 4 to 3984.0 g ofwater. The resulting fluid contained 0.1% Cu-8. The fluid was used totreat southern pine lumber using a full cell process. The treated stakeswere oven dried and found to contain a uniform distribution of particlesthroughout the cross sections and were resistant to fungal and insectattack.

EXAMPLE 13

A preservative treating fluid was prepared by mixing 175 g concentrateddispersion containing 20% copper carbonate and 0.5% cyproconazole with3325.0 g water. The resulting solution contained 1.0% copper carbonateand 0.025% cyproconazole and was used to treat southern pine lumberusing a full cell process. The treated stakes were oven dried and foundto contain a uniform distribution of copper and cyproconazole throughoutthe cross sections and were resistant to fungal and insect attack.

EXAMPLE 14

A preservative treating fluid can be prepared by mixing copper sulfatesolution and micronized cyproconazole at a concentration of 0.25% Cu and0.01% cyproconazole. The resulting fluid can be used to treat lumberusing a full cell process. The treated sample can be air-dried for twoweeks and tested for resistance to fungal and termite attack.

Although specific embodiments have been described herein, those skilledin the art will recognize that routine modifications can be made withoutdeparting from the spirit of the invention.

1-48. (canceled)
 49. A wood preservative composition comprising adispersion of micronized particles selected from the group consisting ofcopper, copper hydroxide, copper carbonate, basic copper carbonate,copper oxychloride, copper 8-hydroxyquinolate, copperdimethyldithiocarbamate, copper omadine, copper borate and combinationsthereof, wherein the size of the particles is between 0.005 to 25microns.
 50. The composition of claim 49, wherein the size of theparticles is between 0.005 and 10 microns.
 51. The composition of claim50, wherein the size of the particles is between 0.05 and 10 microns.52. The composition of claim 51, wherein the size of the particles isbetween 0.05 and 1.0 microns.
 53. The composition of claim 49, furthercomprising an agent selected from the group consisting of waterrepellants, colorants, emulsifying agents, dispersants, stabilizers andUV inhibitors.
 54. The composition of claim 49, further comprising oneor more enhancing agents.
 55. The composition of claim 54, wherein theenhancing agent is a trialkylamine oxide having the following structure:

where R₁ is a linear or cyclic C₈ to C₄₀ saturated or unsaturated groupand R₂ and R₃ independently are linear C₁ to C₄₀ saturated orunsaturated groups.
 56. The composition of claim 54, wherein theenhancing agent is an alkoxylated diamine having the followingstructure:

where n is an integer which can vary from 1 to 4; R₁, R₂ and R₃ areindependently selected from the group consisting of hydrogen, methyl,ethyl and phenyl; a, b and c are each integers from 1 to 6; and R₄ isfatty alkyl of C₈ to C₂₂.